Solar energy has long been looked to as a potential solution to the ever increasing energy needs of the planet's population. Increasing costs of mining fossil fuels, increased concerns over “greenhouse” emissions, and increasing instabilities in regions that house large reserves of fossil fuels have furthered interest in exploiting alternative energy strategies, including solar energy sources.
To date, solar energy conversion has generally relied upon either the direct harvesting of solar thermal energy, e.g., in heating applications, or in thermoelectric conversion, or through the direct conversion of photonic energy to electrical energy through the use of photovoltaic cells.
Current photovoltaic devices or cells employ thin layers of semiconductor material, e.g., crystalline silicon, gallium arsenide, or the like, incorporating a p-n junction to convert solar energy to direct current. While these devices are useful in certain applications, their efficiency has been somewhat limited, yielding conversion efficiencies, e.g. solar power to electrical power, of typically marginally better than 10%. While efficiencies of these devices have been improving through costly improvements to device structure, it is believed that physical limitations on these devices mean they will, at best, achieve a maximum efficiency of around 30%. For ordinary energy requirements, e.g., public consumption, the relative inefficiency of these devices, combined with their relatively high cost, when compared to other means of energy generation, have combined to inhibit the widespread adoption of solar electricity in the consumer markets. Instead, such systems have been primarily used where conventionally generated electricity is unavailable, e.g., in remote locations, terrestrial or otherwise, or where costs associated with bringing conventionally generated electricity, to a location where it is needed, more closely match the costs of photovoltaic systems.
Because of their construction and efficiency, currently marketed photovoltaics also come with a number of physical requirements. For example, because of their relative inefficiency, as well as their rigid construction, photovoltaic systems typically require adequate flat space that has appropriate sun exposure at all times, or at least during peak times, to meet the requirements for electricity for which the system is used.
Despite the issues with current photovoltaic technology, there is still a desire and a need to expand usage of solar electricity. In particular, there is generally a need for an improved photovoltaic cell that has one or more of: increased energy conversion efficiency, decreased manufacturing costs, greater flexibility and/or reasonable durability and/or longevity. The present invention meets these and a variety of other needs.